In an air conditioning system in the background art where a plurality of indoor units are connected with one outdoor unit, controlling is performed by each of the indoor units being specified by identifying using unique information such as a serial number. For example, a technique is proposed in Japanese Unexamined Patent Application Publication No. 2000-74461 where numbering is set for each of the plurality of indoor units as an address in order of the unique serial numbers which are given when manufacturing the indoor units and which are stored on an EEPROM in each of the indoor units. Here, the EEPROM is a component which is included in a print substrate which is provided in an air conditioning unit such as the indoor unit.
In addition, in the air conditioning system where the plurality of indoor units are operated using one remote control unit, setting of addresses for each of the indoor units from the remote control unit in order to identify each of the indoor units is described in Japanese Unexamined Patent Application Publication No. 2000-74461.